EP4166706A1

EP4166706A1 - Device and method for handling tubular knitted articles

Info

Publication number: EP4166706A1
Application number: EP22200635.5A
Authority: EP
Inventors: Gilberto BILIOTTI; Chiaretta BILIOTTI
Original assignee: Bipier Srl
Current assignee: Bipier Srl
Priority date: 2021-10-12
Filing date: 2022-10-10
Publication date: 2023-04-19
Also published as: IT202100026129A1

Abstract

The device (1) comprises a gripping and handling member (51) for gripping and handling the tubular knitted articles (M), which is adapted to engage with a toe (P) of the tubular knitted article (M) when this latter is arranged with the toe (P) up and the elastic edge (B) down. The device further comprise at least one first cylindrical member (71) for angularly positioning the tubular knitted articles. The gripping and handling member (51) is configured to be positioned axially aligned with, and below, the cylindrical member (71), and is provided with a lifting movement for bottom-up loading the tubular knitted article (M) onto the cylindrical member (71) when the gripping and handling member (51) is axially aligned with the cylindrical member (71). The device further comprises an arrangement for angularly and axially positioning the toe of the tubular knitted article (M) on the cylindrical member (71) and a closing machine (5) for closing the toe (P) of the tubular knitted article (M). A transfer arrangement (200) is adapted to prepare the tubular knitted article (M) for being transferred to the closing machine (5).

Description

TECHNICAL FIELD

The present invention relates to the field of textile machines. The invention particularly relates to improvements to the machines and method for handling tubular knitted articles, such as stockings and socks, especially to prepare them for the step of closing the toe. Embodiments disclosed herein relate also to devices performing the closing of the toe of the tubular knitted articles.

BACKGROUND TO THE INVENTION

Tubular knitted articles, such as in particular socks and stockings, are usually manufactured using circular knitting machines. Through knitting, a tubular knitted article is obtained, which is open at both ends. One end constitutes the usually elastic edge, which is destined to remain open in the finished product, whilst the opposite end constitutes the toe of the tubular knitted article, which shall be closed. The toe is usually formed by a pocket of fabric shaped appropriately to match the shape of the foot. Often, between the toe and the open edge of the tubular knitted article a pocket of fabric is provided, forming the heel of the tubular knitted article. The toe is closed along a sewing or linking line, which shall be properly positioned with respect to the pocket(s) of fabric (of the toe and the heel) provided in the tubular knitted article. Due to the presence of the pockets, the tubular knitted article is not axial-symmetrical, and shall be therefore angularly oriented properly before closing the toe.
In some cases, the operation of closing the toe is performed in the same circular knitting machine where the tubular knitted article has been produced. In this way, at the end of the knitting process a finished product is obtained, what has significant advantages in terms of both reduction in the number of machines necessary for producing the knitted articles, and overall dimensions.
However, the devices for closing the toe that are integrated in, or combined with, the circular knitting machine are complex and expensive. The use thereof, and above all the maintenance and repair thereof, require highly specialized workforce. Moreover, one closing device shall be provided in each circular knitting machine, what significantly affects the overall cost of the production line.
In other cases, the operation of closing the toe is performed in closing machines, typically sewing machines, or linking machines, that are outside, and independent of, the circular knitting machine. A single sewing or linking machine can be used for more circular knitting machines.
The tubular knitted articles shall be fed to the closing machines correctly oriented, with the toe kept stretched transversally with respect to the longitudinal extension of the tubular knitted article, on a sewing plane. The sewing plane, and therefore the direction according to which the toe of the tubular knitted article is stretched, shall be angularly oriented with respect to the pockets of the toe and the heel.
Machines and devices have been specifically developed for automating the operations of correctly orienting the tubular knitted articles and preparing it for sewing. A device of this kind is disclosed for example in WO2006/061870
Handling the tubular knitted articles to prepare them for sewing and to insert them in the sewing machine has many difficulties. One of them consists in that the tubular knitted articles may have significantly variable lengths. In the field of socks there are typically knee socks, mid-calf socks, crew socks, ankle socks, low-cut socks and even shorter socks, so-called no-show socks, these latter covering the foot only up to the malleolus. The currently known machines and devices for handling the tubular knitted articles and preparing them for sewing are not flexible and not easily adaptable to articles of variable length. Particularly difficult is to handle short tubular knitted articles.
There is therefore the need, in the hosiery and knitting industry, for machines and devices that overcome the limits and drawbacks of the prior art machines and devices.
In particular, it would be advantageous to have available a closing device for closing the toe of tubular knitted articles, which is flexible and adapted to handle easily, with no difficult adjustments, articles of even very different lengths.

SUMMARY OF THE INVENTION

To solve the drawbacks of the prior art completely or partially, an improved device is provided for handling tubular knitted articles, such as socks and the like.
In some embodiments, the device of the invention also comprises components and members for stretching the tubular knitted article and closing the toe thereof.
Briefly, the device described herein comprises a member for gripping and handling the tubular knitted articles, which is adapted to engage the toe of a tubular knitted article when this latter is arranged with the toe directed upwards and the elastic edge directed downwards; and at least a first cylindrical member, the function of which is to allow the angular positioning of the tubular knitted articles.
The cylindrical member is advantageously supported from the top and has a free lower end, to allow the loading of the tubular knitted articles from the bottom.
The gripping and handling member is configured to be positioned axially aligned with, and below, the cylindrical member, and is provided with a lifting movement for loading the tubular knitted article on the cylindrical member when the gripping and handling member is axially aligned with the cylindrical member.
In this way, the tubular knitted articles are loaded on the cylindrical member in such a way that the toe, which shall be subsequently closed, is engaged with the cylindrical member and directed upward, while the edge remains below the toe, directed downward, and can project beyond the axial extension of the cylindrical member.
This allows to handle tubular knitted articles of various lengths, for example from knee socks to no-show socks, in a flexible and easy way. In fact, all tubular knitted articles are loaded by the same gripping and handling member on the cylindrical member with the same movements, independently of the length of the tubular knitted article.
In embodiments disclosed herein, the device further comprises an arrangement for angularly and axially positioning the toe of the tubular knitted article when the tubular knitted article is on the cylindrical member.
In further embodiments disclosed herein, the device comprises also a closing machine for closing the toe of the tubular knitted article, typically a sewing machine, as well as a transfer arrangement, adapted to prepare the tubular knitted article for being transferred to the sewing machine.
Typically, the transfer arrangement comprises transversal stretching members adapted to transversally stretch the toe of the tubular knitted article loaded on the cylindrical member, the stretching members being adapted to be inserted, with a downward movement, in the toe of the tubular knitted article.
In advantageous embodiments, the device further comprises an opening chamber, which is adapted to open the toe of the tubular knitted articles, and a reversing tube, which has a vertical axis and is adapted to reverse the tubular knitted articles pneumatically.
The reversing tube can be configured to be positioned below the opening chamber. In this case, the gripping and handling member is adapted to be arranged below the opening chamber, between the opening chamber and the reversing tube, to engage the toe of the tubular knitted article when the toe is in the opening chamber. Once the toe has been engaged, the tubular knitted article can be removed from the opening chamber by reversing it inside the reversing tube by means of suction through the reversing tube.
In some embodiments, the cylindrical member and the reversing tube are configured to take an axial alignment position, where the reversing tube is arranged below the cylindrical member. In other embodiments, the reversing tube can be arranged stationary below the opening chamber.
For higher productivity, the device can be a multi-station device, comprising a plurality of cylindrical members supported on a conveyor, for example a carousel rotating around a vertical axis. The conveyor is adapted to transfer each cylindrical member into a sequence of stations along a closed path. In this way, the device is adapted to handle simultaneously a plurality of tubular knitted articles, transferring them to the subsequent stations, where one or more operations are carried out. In the present description and the attached claims, any reference to the cylindrical member shall be intended, in case of a multi-station device with a plurality of cylindrical members, as a reference to every cylindrical member of the device.
In some embodiments, a pneumatic feed duct for feeding the tubular knitted articles is associated with the opening chamber, the feed duct having an inlet and an outlet for the tubular knitted articles, the outlet being arranged coaxial with, and above, the opening chamber. The tubular knitted articles can be inserted into the pneumatic feed duct automatically, semi-automatically or manually. A system can be provided, for example, which automatically takes the tubular knitted articles, which have been previously directed manually or automatically, and insert them into the pneumatic feed duct.
The tubular knitted article moves forward in the pneumatic feed duct by means of appropriately controlled suction.
In some embodiments, to facilitate the opening of the toe of the tubular knitted article, a converging-diverging duct is provided between the outlet of the tubular knitted articles and the opening chamber, the converging-diverging duct being coaxial with the outlet of the tubular knitted articles and the opening chamber.
In some embodiments, to facilitate the opening of the toe and the unloading thereof from the opening chamber, this latter can be fluidly coupled to an annular duct, which surrounds the converging-diverging duct and defines an annular port around the lower end, i.e. the outlet, of the converging-diverging duct, the lower end ending in the opening chamber.
The annular duct is adapted to generate an air flow sucked from the inside of the converging-diverging duct in opposite direction relative to the feed direction of the tubular knitted articles from the pneumatic feed duct to the opening chamber.
In some steps of the cycle of opening the toe and unloading it from the opening chamber, advantageously in the step of transferring the toe to the gripping and handling member, the annular duct is adapted to generate an air flow in the same direction as the feed direction of the tubular knitted article in the pneumatic feed duct.
In advantageous embodiments, to facilitate the insertion of the toe of the tubular knitted article in the opening chamber, a pair of motorized rollers is provided opposite the outlet of the tubular knitted articles, the rollers defining a nip adapted to receive the tubular knitted articles and to move them from the outlet toward the opening chamber. In some embodiments, the pair of motorized rollers is provided between the outlet of the tubular knitted articles and the converging-diverging duct.
In some embodiments, to facilitate some steps of opening the toe of the tubular knitted article, the device can comprise a plurality of air nozzles, which are associated with the outlet of the tubular knitted articles from the pneumatic feed duct, are arranged around an axis of the pneumatic feed duct, and are directed in such a way as to converge toward the axis of the pneumatic feed duct and toward the opening chamber.
In some embodiments, the gripping and handling member comprises a plurality of stretching fingers, which are provided with a movement toward and away from one another with respect to a vertical axis of the gripping and handling member. The gripping and handling member also comprises a plurality of pushing elements, which co-act with the stretching fingers for holding the toe of the tubular knitted article. The stretching fingers are directed upward so as to engage with the toe of a tubular knitted article arranged in the opening chamber. The pushing elements co-act with the stretching fingers to engage with the toe around the terminal edge thereof and to transfer it from the opening chamber to the cylindrical member.
In some embodiments, for better controlling the transfer of the tubular knitted article to the cylindrical member, the reversing tube is provided with a movement from a position of axial alignment with the opening chamber to a position of axial alignment with each cylindrical member, and vice versa. In this case, the reversing tube follows the transfer movement of the gripping and handling member from the position of axial alignment below the opening chamber to the position of axial alignment below the cylindrical member.
In some embodiments, to facilitate the correct loading of the toe of the tubular knitted article on the cylindrical member, the gripping and handling member is combined with an annular element, which is coaxial with the gripping and handling member, vertically movable parallel to the axis of the gripping and handling member, and adapted to move through the gripping and handling member, moving through the fingers thereof when they are spaced from one another. The annular element facilitates the transfer of the toe of the tubular knitted article from the gripping and handling member to the cylindrical member and can be used to stretch the toe, which has been previously folded, when the tubular knitted article is reversed with the toe engaged with the fingers of the gripping and handling member.
In advantageous embodiments, to stretch the toe and arrange the tubular knitted article planar on a geometrical plane directed according to the sewing line of the toe, the cylindrical member comprises a plurality of stretching tabs, which are extractable from and retractable into a side cylindrical surface. To simplify and to facilitate the handling of the tubular knitted article, four extractable tabs are preferably provided.
Further advantageous features and embodiments of the device will be described below with reference to the drawing, and in the attached claims.
According to a further aspect, a method is provided for handling a tubular knitted article, particularly a sock having a toe and an elastic edge, wherein the method includes the steps of:

arranging the tubular knitted article with the toe up and the edge down;
loading the tubular knitted article onto a cylindrical member through an upward movement, engaging the toe of the tubular knitted article with the cylindrical member;
angularly and axially positioning the tubular knitted article with respect to the cylindrical member;
transversally stretching the toe of the tubular knitted article.

In advantageous embodiments, the method can also include the step of transferring the tubular knitted article to a closing machine, and the further step of closing the toe of the tubular knitted article, typically by sewing.
In embodiments disclosed herein, the method comprises the following steps: feeding the tubular knitted article, with the toe ahead, from the top toward an opening chamber; inserting the toe into the opening chamber; opening the toe; engaging the toe with a gripping and handling member; reversing the tubular knitted article by inserting the edge of the tubular knitted article in a reversing tube arranged axially aligned with, and below, the opening chamber, keeping the toe engaged with the gripping and handling member, the gripping and handling member being positioned between the opening chamber and the reversing tube.
In some embodiments, the method also provides for the step of axially aligning the gripping and handling member with the cylindrical member, with the cylindrical member above the gripping and handling member.
The method can also comprise the step of transferring the toe of the tubular knitted article upward from the gripping and handling member to the cylindrical member, and the mentioned step of angularly and axially positioning the tubular knitted article with respect to the cylindrical member.
Once the tubular knitted article has been axially and angularly positioned with respect to the cylindrical member, the step is performed of transversally stretching the toe of the tubular knitted article on a sewing plane and of longitudinally stretching the tubular knitted article.
Lastly, the tubular knitted article is unloaded from the cylindrical member and the transversally stretched toe is inserted into a guide of a sewing machine.
According to a further aspect, a device is provided for closing the toe of tubular knitted articles comprising an elastic edge and a toe, particularly socks, wherein the device includes:

an opening chamber adapted to open the toe of the tubular knitted articles;
a reversing tube, which has a vertical axis, is adapted to reverse the tubular knitted articles pneumatically, and is configured in such a way as to be positioned below, and coaxially with, the opening chamber;
a gripping and handling member for gripping and handling the tubular knitted articles, adapted to engage with the toe of the tubular knitted article and to transfer the tubular knitted article from the opening chamber to the reversing tube;
at least one first cylindrical member for angularly positioning the tubular knitted articles, wherein the first cylindrical member and the reversing tube are configured to take a position of axial alignment, where the reversing tube is arranged below the cylindrical member; wherein the gripping and handling member is configured to transfer the tubular knitted article from the reversing tube to the cylindrical member when the cylindrical member and the reversing tube are axially aligned, engaging the toe of the tubular knitted article with the first cylindrical member;
an arrangement for angularly positioning the toe of the tubular knitted article on the cylindrical member;
a closing machine for closing the toe of the tubular knitted article; and
a transfer arrangement, adapted to transfer the tubular knitted article from the cylindrical member to the sewing machine.

According to a further aspect, a method is provided for closing the toe of a tubular knitted article having a toe and an elastic edge, particularly a sock, the method comprising the following steps:

feeding a tubular knitted article, with the toe ahead, from the top toward an opening chamber;
inserting the toe into the opening chamber;
opening the toe;
engaging the toe with a gripping and handling member;
reversing the tubular knitted article by inserting the edge of the tubular knitted article in a reversing tube arranged axially aligned with, and below, the opening chamber, keeping the toe engaged with the gripping and handling member, the gripping and handling member being positioned between the opening chamber and the reversing tube;
axially aligning the gripping and handling member with the cylindrical member, arranging the cylindrical member above the gripping and handling member;
transferring the toe of the tubular knitted article upward from the gripping and handling member onto the cylindrical member;
angularly and axially positioning the tubular knitted article with respect to the cylindrical member;
unloading the tubular knitted article from the cylindrical member, stretching the toe on a sewing plane; and
inserting the toe into a guide of a closing machine and closing the toe.

BRIEF DESCRIPTION OF THE DRAWING

The invention will be better understood by following the description below and the attached drawing, showing a non-limiting embodiment of the invention. More specifically, in the drawing:

Fig. 1 is a plan view of the device in a first embodiment;
Fig. 2 is an outer side view of the pneumatic feed duct for feeding the tubular knitted articles;
Fig. 3 shows a cross section of the pneumatic feed duct for feeding the tubular knitted articles and of the opening chamber in a working step;
Figs. 4 to 9 show an enlargement of the opening chamber and of the gripping and handling member in a sequence of operating positions for opening the toe of a tubular knitted article and engaging it with the gripping and handling member;
Fig. 10 is an axonometric view of the gripping and handling member;
Figs. 11 to 13 show cross-sections of the gripping and handling member, of the reversing tube and of the cylindrical member in a sequence of steps for transferring the tubular knitted article from the gripping and handling member to the cylindrical member;
Figs. 14(A), (B) and (C) are outer axonometric views and cross-sections of the cylindrical member in different operating positions;
Fig. 15 is a side view of the cylindrical member and of members for axially positioning the tubular knitted article with respect to the cylindrical member;
Fig. 16 is a plan view according to XVI-XVI of Fig. 15;
Fig. 17 is an axonometric view of a gripper, which is part of the members for axially positioning the tubular knitted article with respect to the cylindrical member;
Figs. 18, 19 and 20 show views analogous to those of Figs. 15, 16 and 17 in a subsequent operating step;
Figs. 21, 22 and 23 show axonometric views of the cylindrical member and of devices for angularly positioning the tubular knitted article with respect to the cylindrical member, in various operating positions of a positioning sequence;
Figs. 24, 25 and 26 show axonometric views of the cylindrical member and of devices for axially translating the tubular knitted article along the cylindrical member, in various operating positions of a positioning sequence;
Figs. 27, 28, 29, 30 and 31 are axonometric views of the cylindrical member and of parts of a transfer arrangement in an operating sequence of removing the tubular knitted article from the cylindrical member and stretching the toe of the tubular knitted article on a sewing plane;
Figs. 32, 33, 34, 35, 36, 37, 38, 39 and 40 show axonometric views of part of the transfer arrangement in an operating sequence of longitudinal stretching the toe of the tubular knitted article and transferring to the sewing machine.

DETAILED DESCRIPTION

In the present description and in the attached claims, the terms above, below, up, down, upper, lower, and any further similar term indicating positions in the space, refer to the position of the respective members or the movements thereof when the device is working. Furthermore, the term "vertical" indicates a direction parallel to the gravity direction, and the term "horizontal" indicates a direction orthogonal to the gravity direction.
In the description below, reference will be specifically made to the handling and sewing of socks as example of tubular knitted articles, but this shall be intended as a non-limiting example.
Fig. 1 shows a simplified plan view of a device according to the invention, in a multi-station configuration. The device, indicated with the reference number 1, comprises a part 3, which includes members performing the operations of handling and preparing the tubular knitted articles, and a closing machine 5, for closing the toe of the socks, here below referred to also as "sewing machine".
In the illustrated embodiment, the part 3 of the device 1 includes an initial section 7, which comprises a pneumatic feed duct for feeding the socks to an opening chamber and a series of stations, in which the open sock, taken from the initial section 7, is handled, performing on it the operations necessary for the insertion thereof in the sewing machine 5.
The device 1 further comprises, in the part 3, a sequence of stations where the various operations necessary to prepare the sock to be loaded in the closing machine 5 are performed. In the illustrated embodiment, the device 1 comprises six stations, but it is also possible to provide a device with a lower or higher number of stations. In the illustrated embodiment, one of the six stations is a neutral station. More in particular, the six stations are indicated by 9A, 9B, 9C, 9D, 9E and 9F. The station 9F is the neutral station.
As it will be described in greater detail below, in the station 9A the sock is loaded, from the bottom upward and with the toe facing upward, onto a cylindrical member, which transfers the sock through the subsequent stations and on which the toe is handled to be positioned stretched transversally in a direction parallel to the direction along which it shall be sewn, i.e. according to the sewing line that will be performed in the closing machine 5.
Briefly, in the station 9B a first axial translation of the sock onto the cylindrical member is performed. In the station 9C, the operation is performed of angularly positioning the sock with respect to the cylindrical member. In the station 9D, the operation is performed of further axially positioning the sock with respect to the cylindrical member, and in the station 9E the operation is performed of stretching the toe of the sock in transversal and longitudinal direction with respect to the longitudinal extension of the sock, to prepare it for sewing, that is then performed in the sewing machine 5, where every sock is transferred through a transfer arrangement, described hereunder.
In this embodiment, the device is a multi-station device, therefore it comprises a plurality of equal cylindrical members, each of which receives a single sock and transfers it from one to the other of the various stations to perform the various operations required by the operating cycle. The single cylindrical members, that will be described in greater detail below, are supported on a conveyor, which is represented, in the illustrated example, by a carousel 11 rotating around a vertical axis 11A. The arrow f11 indicates the rotation (counterclockwise in the illustrated example) of the carousel 11. Even if the configuration of the carousel conveyor is currently preferred, it is also possible to use a different conveyor, provided that it is adapted to transfer the cylindrical members from one to the other of the various operating stations 9A, 9B, 9C, 9D, 9E, 9F along a closed path. A belt conveyor can be used, for example.
In general, the conveyor 11 is arranged at a higher level and the cylindrical members hang from the top and project downward from the conveyor 11, in such a way as to allow loading the tubular knitted articles from the bottom upward.
Just by way of example, the conveyor 11 comprises a star-like structure with six arms, each of which carries a cylindrical member, which is arranged with the vertical axis projecting below the conveyor 11 and is not shown in Fig. 1. Figs. 14(A), 14(B) and 14(C) show a cylindrical member and the inner structure thereof. The structure of the cylindrical member will be described below.
The initial section 7, the stations 9A, 9B, 9C, 9D, 9E with the related mechanisms, as well as the functions performed in each section and station of the device, will be described below.
Specifically, Figs. 2 to 10 show a pneumatic feed duct 13 for feeding socks M and the members used for opening the toe P of the sock M and for gripping and handling the sock.
In an embodiment, the pneumatic feed duct 13 for feeding the socks (Figs. 2 to 9) comprises an inlet 13A, where the socks M are inserted, and an outlet 13B, from which the socks M are unloaded toward an opening chamber 15 arranged below the outlet 13B.
Characteristically, the socks M are inserted in the inlet 13A of the pneumatic feed duct 13 directed in such a way that the toe P of the sock M is in a leading position with respect to the elastic edge B of the sock M, i.e. the socks are directed with the toe P ahead with respect to the feed direction of the socks M in the pneumatic feed duct 13. To this end, each individual sock M is inserted into the pneumatic feed duct 13 correctly oriented by an operator, who directs the socks by hand, inserting them with the toe P ahead. In further embodiments, the socks M are directed automatically using an appropriate device, that does not constitute an object of the present invention.
In general, the socks M come from one or more circular knitting machines (not shown), and have an open toe P, which shall be closed by the sewing machine 5.
As shown in Fig. 3, to move each sock M forward, from the inlet 13A toward the outlet 13B, an air flow is generated in the pneumatic feed duct 13 through a fan, not shown, coupled to a suction mouth 17. An air flow F is generated by the suction mouth 17, sucked through holes 13C provided in a cylindrical wall portion 13D of the pneumatic feed duct 13 (see enlargement of Fig. 4).
In some embodiments, for performing some handling operations, described below, on the sock M, along the pneumatic feed duct 13 a gate 19 is provided for closing the pneumatic feed duct 13. A side discharge duct 21 is provided for discharging defecting socks, or socks on which, for any reason, it is impossible to perform the operations of opening the toe. The side discharge duct 21 ends in a discharge bell 23, from which the socks, sucked in the discharge side duct 21, are discharged by gravity. Reference number 27 indicates an auxiliary suction mouth, through which a fan 29 generates a sucked air flow for sucking a sock M from the pneumatic feed duct 13, closing the gate 19.
In the illustrated embodiment, members are provided between the outlet 13B and the opening chamber 15, which facilitate the transfer of the toe P of the sock M toward the opening chamber 15, where the toe is stretched. Just by way of example, in the illustrated embodiment a pair of motorized rollers 31 is provided, which define a nip 33 (see Fig. 4). The motorized rollers 31 have rotation axes parallel to each other and oriented at 90° with respect to the axis of the pneumatic feed duct 13.
Furthermore, near the outlet 13B the pneumatic feed duct 13 has a plurality of nozzles 35 (see Fig. 4) distributed around the axis of the pneumatic feed duct 13 for supplying pressurized air. The nozzles 35 are directed downward, i.e. toward the opening chamber 15 and the pair of motorized rollers 31, and converge toward the axis of the pneumatic feed duct 13.
In the illustrated embodiment, a converging-diverging duct 37 is provided between the pair of motorized rollers 31 and the opening chamber 15, the duct being coaxial with the outlet 13B of the pneumatic feed duct 13 and with the opening chamber 15. The converging-diverging duct 37 has a converging portion 37A arranged upstream (with respect to the feed direction of the socks M), and a diverging portion 37B arranged downstream. The converging portion 37A has a mouth directed toward the motorized rollers 31, and the diverging portion 37B ends in the opening chamber 15.
Around the lower end of the converging-diverging duct a truncated-conical surface 39 is provided, with a wide opening angle, surrounding the outlet of the converging-diverging duct 37.
An annular duct 41 can extend around the converging-diverging duct 37, the annular duct surrounding the converging-diverging duct 37 and, in the illustrated example, defining an annular port 41A between the truncated-conical surface 39 and the lower end of the converging-diverging duct 37. As it will be clearly apparent from the description below, an air flow is generated in the annular duct 41 in a direction toward the opening chamber 15 and in opposite direction in different steps of the sock handling process, for the purposes explained below.
The air flow in the annular duct 41 is generated by a toroidal tube 43, which extends around the axis A-A of the pneumatic feed duct 13 and of the converging-diverging duct 37. The opening chamber 15 can be depressurized through suction generated in the annular duct 41. To this end, the bottom of the opening chamber 15 is provided with an opening-closing door 45. When the door 45 is closed (Fig. 4), it is possible to depressurize the opening chamber 15 by sucking air through the annular duct 41.
The function of the pneumatic feed duct 13 and of the opening chamber 15, with the intermediate members mentioned above, will be described below with specific reference to the sequence of Figs. 4 to 7, showing an enlargement of the end part of the pneumatic feed duct 13 and of the opening chamber 15, in a cross section according to a plane containing the axis A-A.
Fig. 4 shows the step where a new sock M, the toe P whereof shall be stretched, is sucked through the air flow F generated by the suction mouth 17. Fig. 5 shows the subsequent step, where, after the suction by the mouth 17 has ended, the toe P of the sock M is pushed into the nip 33 between the motorized rollers 31 through air flows F2 generated by the nozzles 35. The nozzles 35 are kept in rotation (arrow f31, Fig. 5), in such a direction as to hold the toe P and to pull it downward, making it exit the nip 33 toward the converging-diverging duct 37.
The opening chamber 15 is temporarily closed by the door 45 and a suction flow is generated in the annular duct 41 by the toroidal tube 43 through the annular port 41A. The suction flow is indicated by F3 in Fig. 6. The suction flow F3, in combination with the rotation of the motorized rollers 31 according to the arrow f31, makes the toe P of the sock M enter the converging-diverging duct 37 and move forward to the opening chamber 15. Thanks to the suction through the annular port 41A, the toe P is opened and the fabric forming it is stretched and adheres to the truncated-conical surface 39, as shown in Fig. 6.
To perform the subsequent operations on the sock M, the toe P, which has been stretched through the above-described operations performed in the opening chamber 15, shall be engaged and handled in the subsequent steps, until to the sewing step. To this end, the device 1 comprises a gripping and handling member 51, illustrated alone in Fig. 10, co-acting with the opening chamber 15 to perform the operations illustrated in Figs. 7 to 9, which show the end part of the pneumatic feed duct 13, the opening chamber 15 and the gripping and handling member 51.
Before describing the operations performed in Figs. 7 to 9, the overall structure of the gripping and handling member 51 will be described with reference to Fig. 10.
In the illustrated embodiment, the gripping and handling member 51 comprises an annular base 53, on which four operating units 55 are provided. Each operating unit 55 comprises a stretching finger 57, which is provided with a radial movement according to the arrows f57 to be arranged in a position of minimal distance from the other fingers, shown in Fig. 10, and in a stretched position, where it is radially translated outwards with respect to a vertical axis, indicated by B-B in Fig. 10. The stretching fingers 57 are directed upward.
Each operating unit 55 further comprises one pushing element 59 for each finger 57. The pushing elements 59 are provided with a radial movement according to the arrows f57, independent of the movement of the fingers 57, so that each finger 57 and the respective pushing element 59 can move toward and away from each other for the purposes described below.
Each operating unit 55 also comprises a first actuator 61, for controlling the radial movement of the respective finger 57, and a second actuator 63, for controlling the radial movement of the respective pushing element 59.
The operation of the gripping and handling member 51 will be explained below with reference to Figs. 7 to 13.
Fig. 7 shows the initial step of the operations performed by the gripping and handling member 51 to remove the sock M from the pneumatic feed duct 13 and to transfer it to the first station 9A. In Fig. 7, the gripping and handling member 51 is arranged below, and coaxial with, the opening chamber 15, with the axes A-A and B-B coinciding with each another. The stretching fingers 57 are directed upward and are adjacent to one another, i.e. in the position of minimal distance from one another and from the axis A-A. The pushing elements 59 are spaced, i.e. they are in a position radially far from the axis A-A.
The door 45 has been opened through a movement according to the arrow f45. An air flow directed toward the opening chamber 15 is generated through the annular port 41A and the annular duct 41, the air flow detaching the toe P from the annular port 41A and pushing it toward the stretching fingers 57. In this step, the motorized rollers 31 continue rotating, making the sock M move downward. The distance, in vertical direction, between the stretching fingers 57 and the opening chamber 15 is such that the toe P of the sock M is able to surround the stretching fingers 57, i.e. the fabric forming the toe P is arranged around the stretching fingers 57.
In the subsequent step, illustrated in Fig. 8, the stretching fingers 57 move away from one another in radial direction, thus stretching the toe P of the sock M.
Subsequently, or at the same time, the pushing elements 59 are translated in radial direction according to the arrows f59 (Fig. 9) to move toward the axis A-A, B-B, so that each pushing element 59 blocks a portion of the toe P of the sock M against the respective finger 57, in order to hold the toe of the sock M when this latter is sucked in a reversing tube 65 that, in the meantime, has been arranged axially aligned along the axis A-A with, and below, the opening chamber 15. To this end, the sock M is released by the motorized rollers 31, which continue rotating until to completely release the sock M downward. The sock M is inserted in the reversing tube 65 by means of air sucked through a suction mouth, not shown, which is connected to the lower end of the reversing tube 65 and generates a flow of sucked air shown in Fig. 9.
An annular element 67 is provided around the reversing tube 65, the element being provided with an upward and downward movement parallel to the axis of the reversing tube 65 and the axis B-B of the gripping and handling member 51, for the purposes that will be explained below with reference to Figs. 11 to 13.
In addition to the function of taking the sock M from the opening chamber 15 engaging it at the toe P, the gripping and handling member 51 has also the function of transferring the sock, reversed through the reversing tube 65, toward the first station 9A. In the station 9A, the sock M is loaded from the bottom upward on one of the cylindrical members carried by the carousel conveyor 11. Fig. 11 shows a cross section of the carousel conveyor 11 according to a vertical plane. In the figure, only three of the six cylindrical members carried by the carousel conveyor 11 are shown. Each cylindrical member is indicated by the reference number 71. The structure of the cylindrical members 71 is illustrated in greater detail in Figs. 14A, 14B, 14C, to which reference will be made below. Now, it should be noted that each cylindrical member 71 has a cylindrical side surface 73, from which extractable stretching tabs 75 can be extracted with a radial movement relative to the axis C-C of each cylindrical member 71.
As shown in Fig. 11, the set including the gripping and handling member 51 and the reversing tube 65, with the annular element 67 arranged around this latter, has a translation movement in vertical and horizontal direction, indicated by the two arrows Fx, Fy, to move from a position coaxial with, and below, the opening chamber 15 to a position coaxial with, and below, the cylindrical member 71, which is temporarily positioned in station 9A (Fig. 1). In the position of Fig. 11 the gripping and handling member 51, the reversing tube 65 and the cylindrical member 71 that are in the station 9A are coaxial with one another (axis C-C). The sock M is hold at the toe P by the gripping and handling member 51, and the edge B of the sock is kept inside the reversing tube 65.
It is also possible for the reversing tube 65 to constantly remain in a position axially aligned with the opening chamber 15, instead of translating with the gripping and handling member 51 and the annular element 67, which shall be able to be positioned axially aligned with the opening chamber 15 (and with the reversing tube 65) and with the cylindrical member 71 respectively.
Figs. 12 and 13 show the operation of transferring the sock M, by means of the gripping and handling member 51, onto the cylindrical member 71 with an upward movement (arrow Fc in Fig. 12).
As shown in Fig. 13, the gripping and handling member 51 is translated upward to such an extent as to bring the toe P of the sock M to a level higher than that of the upper end (surface 71A) of the cylindrical member 71. The level to which the sock M is lifted is independent of the length of the sock. In fact, what is important is that the toe P of the sock M is brought above the cylindrical member 71, and not the level achieved by the edge B of the sock M. The annular element 67 translates upward synchronously with the gripping and handling member 51, so as to be arranged around the cylindrical member 71, thus surrounding the sock M.
In the subsequent step, shown in Fig. 13, the sock M is unloaded by the gripping and handling member 51 and released on the cylindrical member 71. This operation is performed by moving the stretching fingers 57 and the pushing elements 59 away from one another in radial direction (arrow Fd), to create an annular space, through which the annular element 67 is translated upward according to arrow Fe. The radial outward stroke of the stretching fingers 57 is slightly shorter than the radial outward stroke of the pushing elements 59, so that the toe P is released. The annular element 65 moves upward up to such a level above the cylindrical member 71 that the toe P is arranged above the upper edge of the cylindrical member 71, i.e. above the surface 71A, as shown in Fig. 13. The movement of the stretching fingers 57 away from the axis of the gripping and handling member 51 and the movement of the pushing elements 59 away from the respective stretching fingers 57 allow the passage of the annular element 67 through the gripping and handling member 51 and the removal of the toe P from the stretching fingers, so that the sock M is completely removed from the gripping and handling member 51 and loaded on the cylindrical member 71, with the toe P arranged above the upper surface or face 71A of the cylindrical member 71.
Once the sock M has been transferred on the cylindrical member 71 in the position shown in Fig. 13, the cylindrical member 71 is translated, in subsequent steps, to the stations 9B, 9C and 9D to perform further operations for positioning the sock M on the cylindrical member 71. These operations, and the members performing them, arranged in the stations 9B, 9C and 9D, will be described below with reference to Figs. 15 to 26.
More specifically, in Figs. 15 to 20 the members of the station 9B and the operations they perform are shown. Fig. 15 is a side view, Fig. 16 is a plan view according to XVI-XVI of Fig. 15, and Fig. 17 is an axonometric view of a component of the station 9B.
In the station 9B the sock M is handled so that the toe P is arranged stretched on the upper surface 71A of the cylindrical member 71.
To this end, a first gripper 81 is provided in the station 9B, with two jaws 81A having concave cylindrical gripping surfaces, complementary to the cylindrical side surface 73 of the cylindrical member 71. The axonometric view of Fig. 17 shows in detail the gripper 81 with the open jaws 81A. An optical device is also provided in the station 9B, for facilitating the positioning of the sock M on the cylindrical member 71.
The optical device is part of a detection system for detecting the axial and angular position of the sock M on the cylindrical member 71.
The optical device comprises photocells 83 with respective emitters 83A and receivers 83B (see Figs. 15 and 16). The photocells 83 are arranged in such a way that the optical beams 83F that they generate are parallel to one another, are parallel to the upper surface 71A of the cylindrical member 71, this latter being arranged in the station 9B, and are at a slightly higher level than the upper surface 71A. Specifically, the distance between the optical beams 83F and the upper surface 71A is approximately equal to the thickness of the fabric forming the toe P of the sock M.
For axially positioning the sock M in such a way that the toe P is stretched on the upper surface 71A of the cylindrical member 71, the elements of the station 9B described above perform the following operations. Through rotation of the carousel conveyor 11, the cylindrical member 71, on which the sock M has been loaded, is arranged opposite the first gripper 81, between the emitters 83A and the and receivers 83B of the photocells 83, while the jaws 81A of the gripper 81 are open. This condition is shown in Figs. 15, 16 and 17. The photocells are positioned in such a way that the beams thereof do not interfere with the upper support 74 of the cylindrical member 71 but are intercepted by the portion of fabric forming the toe P of the sock M projecting beyond the upper surface 71A of the cylindrical member 71.
Then, the jaws 81A of the gripper 81 are closed, thus surrounding the cylindrical member 71 and pushing, with the concave gripping surfaces, against the fabric forming the sock M, as shown in Figs. 18, 19 and 20. The gripper 81 is lowered with a vertical movement according to the arrow Ff (Fig. 18). Thanks to the fact that the cylindrical side surface 73 of the cylindrical member 71 has a friction coefficient substantially lower than that of the concave gripping surfaces of the jaws 81A, the downward movement of the gripper 81 (arrow Ff) makes the sock M slide along the cylindrical member 71. The downward movement of the gripper 81 is stopped when the beams 83F of the photocells 83 are freed from the fabric forming the toe P, which is stretched on the upper surface 71A of the cylindrical member 71. This final position is shown in Figs. 18, 19.
Once the above-described operations have been performed in the station 9B, the sock M is transferred, through rotation of the carousel conveyor 11, to the subsequent station 9C, the components and operations of which are illustrated in Figs. 21 to 23. The function of the station 9C is that of angularly positioning the sock M in the correct position with respect to the cylindrical member 71, on which it has been loaded.
To this end, a second gripper 91 is provided in the station 9C, which is equipped with jaws 91A and is substantially equal to the gripper 81 of the station 9B. In the position of Fig. 21, the jaws 91A of the gripper 91 are open and allow to position the cylindrical member 71, with the sock M loaded on it, in the station 9C through rotation of the carousel conveyor 11.
In the illustrated embodiment, an optical device is provided in the station 9C to facilitate the proper angular positioning of the sock M on the cylindrical member 71. The optical device is part of the detection system for detecting the axial and angular position of the sock M relative to the cylindrical member 71.
It should be understood that the optical device of the station 9C, as well as the optical device of the station 9B, can be replaced, if necessary, with other devices having similar functions of detecting the position of the sock M and of controlling the movement of the mechanical members based on this position. For example, capacitive systems, vision systems with video cameras, or other similar systems can be used.
In the illustrated embodiment, the optical device of the station 9C comprises a photocell 93 with an emitter and a receiver that are arranged in the same position; in this way, when the upper surface 71A of the cylindrical member 71 is free from the fabric forming the toe P of the sock M, the optical beam 93F generated by the photocell 93 is reflected by this surface and detected by the receiver. In view of what described above, in this step the toe P is arranged stretched on the upper surface 71A of the cylindrical member 71. The toe P of the sock M is shaped like a pocket, and for this reason the fabric forming it covers only a portion of the upper surface 71A of the cylindrical member 71, as shown in Fig. 21. Therefore, if the beam 93F hits the portion free from fabric of the upper surface 71A, it is reflected, otherwise it is absorbed by the fabric. In the first case, the receiver of the photocell receives a reflected signal, in the second case the receiver does not receive any reflected signal.
The angular positioning of the sock M relative to the cylindrical member 71 is performed as explained below. Once the position of Fig. 21 has been achieved, a gear 76 hinged on the support 74 of the cylindrical member 71 is engaged by a pinion 95 driven into rotation by a motor 97. The engagement between the pinion 95 and the gear 76 occurs through a vertical downward movement of the pinion 95. This movement is shown in Fig. 22, indicated by the arrow Fg, with the gear 76 engaging with the pinion 95. In this position, through the pair pinion 95 - gear 76, the motor 97 drives the cylindrical member 71 into rotation. Due to this rotation, the beam 93F of the photocell 93 hits alternatively the fabric of the toe P or the reflecting upper surface 71A of the cylindrical member 71. In this way, based on the signal detected by the receiver of the photocell 93 and on the signal of an angular encoder, if any, detecting the rotation of the cylindrical member around the rotation axis C-C, it is possible to detect the position of the final edge of the toe P and to stop the cylindrical member 71 when the toe P of the sock M is in a given angular position relative to the rotation axis of the cylindrical member 71. This is possible because, in this step, both the cylindrical member 71 and the sock M rotate around the rotation axis C-C of the cylindrical member 71.
Once the given angular position has been achieved, the jaws 91A of the second gripper 91 are closed, as shown in Fig. 23, and the cylindrical member 71 starts rotating again, controlled by the motor 97. But now the sock M, held by the closed gripper 91, is not involved in the rotation of the cylindrical member 71. Essentially, the cylindrical member 71 rotates inside the sock M held by the gripper 91, with the cylindrical side surface 73 of the cylindrical member 71 sliding on the inner surface of the sock M. The purpose of the relative rotation between sock M and cylindrical member 71 is to bring the stretching tabs 75, extractable from the cylindrical member 71, to a precise position relative to the pocket of fabric, which forms the toe P and which has been stretched on the upper surface 71A of the cylindrical member 71.
In fact, the extractable stretching tabs 75 define the plane where the toe P will be sewn. The plane shall be arranged in such a position relative to the pocket of fabric forming the toe that the sewing line is in the right position relative to the pocket of the toe and to the pocket of the heel of the sock M.
Substantially, thanks to the relative rotation between sock M and cylindrical member 71, and the consequent angular positioning of the sock M relative to the cylindrical member 71, in the subsequent operations the sock M can be inserted in the right position inside the sewing machine 5 (Fig. 1).
In practice, the final position of the sock M relative to the cylindrical member 71 is such that the sewing plane, defined by two coplanar extractable stretching tabs 75, pass through two points (indicated by Pp in Fig. 23) where the tail edge of the toe P touches the circular edge of the upper surface 71A of the cylindrical member 71.
Figs. 24, 25 and 26 show the operations performed on the sock M in the subsequent station 9D, and the members used for performing these operations. In practice, in the station 9D the sock M is axially positioned in the proper position on the cylindrical member 71. To this end, in the station 9D a detection device is provided for detecting the position, which is, in this example again, an optical device and comprises a photocell 101 with an emitter 101A and a receiver 101B. The detection device is also part of the detection system for detecting the axial and angular position of the tubular knitted article relative to the cylindrical member.
In the station 9D, a horizontally movable pushing element 103 and a motorized roller 105 are also provided.
For properly positioning the sock M axially along the cylindrical member 71, the cylindrical member 71 is arranged between the pushing element 103 and the motorized roller 105 (Fig. 24); then, the motorized roller 105 and the pushing element 103 are brought, through movements according to the arrows Fm and Fn, to touch the sock M and are pressed against the cylindrical side surface 73 of the cylindrical member 71, as shown in Fig. 25. The motorized roller 105 is driven into rotation (arrow Fo) to lower the toe P according to the arrow Fp until to arrange it completely on the cylindrical side surface 73 of the cylindrical member 71. The movement according to the arrow Fp is performed only by the pocket of fabric, which initially touched the upper surface 71A of the cylindrical member 71, whilst the remaining part of the fabric of the sock M is held by the pushing element 103, which prevents it from sliding downward. The result is illustrated in Fig. 25, where the terminal edge (indicated by PI) of the toe P of the sock M is completely arranged around the cylindrical side surface 73 of the cylindrical member 71. The desired final position is detected by the photocell 101.
At this point, the extractable stretching tabs 75 are extracted from the cylindrical member 71 as shown in Fig. 26, after having moved the pushing element 103 and the motorized roller 105 away from the cylindrical member 71. Figs. 14(A), 14(B) and 14(C) show in detail the extraction movement and the configuration of the extractable stretching tabs 75; wherein Fig. 14(A) shows an axonometric view of the tabs in extracted position while Figs. 14(B) and 14(C) show an axonometric view in longitudinal cross section with the tabs respectively extracted and retracted. The figures also show a mechanism that can be used for controlling the extraction/retraction movement.
Thanks to the above-described operations of angularly and axially positioning the sock M on the cylindrical member 71, performed before the extractable stretching tabs 75 are extracted, the pocket of fabric forming the toe P is correctly positioned relative to the position of the extractable stretching tabs 75, which define the plane, along which the toe P will be closed by sewing.
The stretching performed by the extractable stretching tabs 75 prepares the sock M to be removed from the cylindrical member 71 in the station 9E, to be transversally and longitudinally stretched and then transferred to the sewing machine 5 through a transfer arrangement, the structure and function whereof will be described below with reference to Figs. 27 to 40. The transfer arrangement is provided partially in the station 9E and partially movable between the station 9E and the sewing machine 5.
With reference to Fig. 28, in the station 9E a vertical guide 121 is provided, along which a first slide 123 is vertically movable according to the double arrow f123. The vertical movement is controlled by an electric motor 125, the rotation movement of which is transferred to a threaded bar 127, integral with the vertically movable first slide 123.
On the slide 123, a stretching unit 129 is provided, carrying a plurality of stretching elements adapted to be inserted in the open toe P of the tubular knitted article M and to stretch the toe P of the tubular knitted article M, arranging it on the sewing plane.
In the illustrated embodiment, the stretching elements comprise a pair of stretching fingers 131, symmetrically movable relative to one another according to the double arrows f131, so as to move toward and away from one another in symmetrical fashion. The stretching unit 129 further comprises a pair of further stretching fingers 133, horizontally movable according to a direction orthogonal to the plane where the stretching fingers 131 move.
In practice, the plane on which the stretching fingers 131 move is the sewing plane of the toe P. In other words, the sewing line that the sewing machine 5 will generate on the toe P will extend in the direction, along which the toe P is stretched by the stretching fingers 131.
As shown in the sequence of Figs. 27, 28 and 29, the cylindrical member 71, on which the sock M has been angularly and axially positioned, is transferred into the station 9E and positioned in front of the guides 121 at a lower level than the stretching unit 129 (Fig. 27); then, the stretching unit 129 is moved forward horizontally according to the arrow f129 (Fig. 28) until to bring the stretching fingers 131, 133 above the sock M kept stretched on the extractable stretching tabs 75 (Fig. 28). At this point, the slide 123 is lowered according to the arrow f123 (Fig. 29), making the stretching fingers 131 and 133 enter, with a downward movement, inside the toe P of the sock M kept stretched by the extractable stretching tabs 75.
To unload the sock M from the cylindrical member 71, the stretching tabs 75 are retracted according to the arrows f75, and the first slide 123 is lowered according to the arrow f123 in Fig. 30. The stretching fingers 131 are moved away from one another according to the arrows f131, transversally stretching the toe P of the sock M. Advantageously, as shown in Fig. 30, the stretching fingers 133 are kept in back position with respect to the plane where the stretching fingers 131 lie.
In the subsequent step, shown in Fig. 31, the stretching fingers 133 are brought (movement f133) in coplanar position relative to the stretching fingers 131, and the stretching unit 129 is moved backward with a horizontal translation movement according to the arrow f129, so as to be moved toward the guides 121.
Once this position has been achieved, a second slide 141, which is part of the transfer arrangement for transferring the sock M from the cylindrical member 71 to the sewing machine 5, is horizontally translated according to the arrow f141 (Fig. 32), so as to engage the sock M.
In the illustrated embodiment, the second slide 141 carries two parallel horizontal shelves 143, shown in particular in Figs. 33 to 40, on which members are provided, substantially symmetrical with respect to a vertical plane, for longitudinally stretching the sock M to insert it into a guillotine guide 6 (see Fig. 1 and Figs. 39, 40) of the sewing machine 5. These members comprise two pairs of opposite pads 145, horizontally movable according to the arrows f145 (Fig. 34) so as to move toward and away from one another with symmetrical movements with respect to the lying plane of the toe P of the sock M, which is physically defined by the stretching fingers 131, 133 when they are coplanar with one another. Two pads 145, carried by one of the two shelves 143, carry respective needles 146, adapted to be inserted in corresponding holes of the opposite pads 145, carried by the other of the two shelves 143.
The members carried by the second slide 141 can also comprise a pair of opposite horizontal blades 147, arranged below the pads 145 and provided with a horizontal movement parallel to, but independent of, the movement f145 of the pads 145.
Below the blades 147, the second slide 141 carries a longitudinal stretching device 150, which comprises two bars 149, symmetrical with respect to a vertical plane and movable with a horizontal movement parallel to the movement of the blades 147 and to the movement of the pads 145, and further movable in vertical direction according to the arrows f149, see Fig. 36. The two bars 149 essentially form the jaws of a longitudinal stretching gripper.
The members described above, carried by the second slide 141 and being part of the transfer arrangement indicated as a whole by the reference number 200, perform the subsequent operating cycle illustrated in the sequence of Figs. 32 to 40.
As already mentioned, in Fig. 32 the second slide 141 is arranged with the two shelves 143 adjacent to the sock M, which is held in transversally stretched position by the stretching fingers 131. Fig. 33 shows a side view of this position. In the subsequent step, illustrated in Fig. 34, the opposite pads 145 are translated according to the arrow f145 toward each other symmetrically with respect to the lying plane of the toe P of the sock M and of the stretching fingers 131, so as to engage, through the needles 146, with the toe P at the terminal edge P1 thereof. The terminal edge P1 is intended to be cut away once the toe P has been sewn.
In the subsequent step, illustrated in Fig. 35, the first slide 123 has been lifted with a vertical translation movement according to the arrow f123, so as to remove the stretching fingers 131 and 133 from the sock M.
Then, as shown in Fig. 36, the bars 149 of the vertical stretching device 150 are pressed against each other, to engage the terminal edge P1 of the sock M, and translated vertically downward to stretch the toe P of the sock M. Arrows f149 in Fig. 36 illustrate this double movement of the bars 149 in horizontal direction, for moving toward each other and in vertical direction for stretching the toe P.
Once this condition of longitudinal stretching of the sock M has been achieved, the blades 147 are pressed against one another with a movement according to the arrow f147, as illustrated in Fig. 37, to engage the toe P of the sock M immediately below the terminal edge PI, which is still engaged by the needles 146 of the pads 145.
The first operation of longitudinal stretching described above, performed by the gripper formed by the bars 149, is useful to stretch the knitted fabric of the sock M between the terminal edge PI, intended to be removed after the toe P has been sewn, and the remaining part of the sock M, to allow the blades 147 to engage with the sock M near the terminal edge P1 of the toe P.
Once this operation has been performed, and after having engaged the sock M below the terminal edge P1 through the blades 147, the pads 145 are moved away from one another, thus releasing the needles 146 from the terminal edge P1 of the toe P. Analogously, the bars 149 of the longitudinal stretching device 150 are released from the sock M and brought to the initial position, with a horizontal and vertical translation movement. These movements are shown in Fig. 38.
In the subsequent step, illustrated in Fig. 39, the bars 149 of the longitudinal stretching device are pressed again against one another with a horizontal movement, and are translated downward with a vertical movement (movements indicated again by the arrows f149), so as to longitudinally stretch the toe P of the sock M, preparing it to be inserted in the guillotine guide 6 of the sewing machine 5.
In the subsequent step, illustrated in Fig. 40, the toe P of the sock M in inserted in the guillotine guide 6 of the sewing machine 5.
In the illustrated embodiment, this operation is performed by translating the guillotine guide 6 toward the station 9E to load the sock M on it.
To this end, as shown in Fig. 1, the guillotine guide 6 is mounted on a carriage 8, which translates according to the double arrow f8. Fig. 40 shows a step where the guillotine guide 6 has been inserted into the station 9E.
During this step, the toe P of the sock M is kept transversally and longitudinally stretched by the members described above, carried by the second slide 141 and in particular by the blades 147 and the bars 149 of the longitudinal stretching device 150. In this way, the sock M properly engages with the guillotine guide 6, arranged between the horizontal blades 147 and the bars 149 of the longitudinal stretching device 150, directly below the horizontal blades 147.
Once the guillotine guide 6 has engaged the sock M, this latter is released by the blades 147 and the bars 149 that open, and the carriage 8 is translated from the station 9E to the sewing machine 5, where the toe P is sewn in a known manner.
The cylindrical member 71, from which the sock M has been previously unloaded, is transferred, through rotation of the carousel conveyor 11, from the station 9E to the neutral station 9F and then to the station 9A to receive a new sock M.
The device described above and illustrated in the drawing is designed as a multi-station device comprising six stations, one of which (the station 9F) is a transfer station, i.e. a neutral station. However, it is also possible to provide devices with a different number of stations, for example omitting the neutral or passage station 9F and/or unifying more members in one station to perform more operation on the sock while the cylindrical member, on which the sock is loaded, remains still in the station. If necessary, a device with a single cylindrical member 71 can be provided, wherein the other mechanical members translate with respect thereto to perform the various operations described above.
However, the multi-station device described above, where the operations are performed in subsequent stations, is a particularly advantageous solution, as it allows high productivity, i.e. high working speed. In this way, the device 1 can be used for handling and sewing socks coming from a high number of circular knitting machines, thus reducing the cost of the production line.

Claims

A device for handling tubular knitted articles comprising an elastic edge and a toe, particularly socks, wherein the device includes:
a gripping and handling member for gripping and handling the tubular knitted articles, which is adapted to engage with a toe of the tubular knitted article when this latter is arranged with the toe up and the elastic edge down;

at least a first cylindrical member; wherein the gripping and handling member is configured to be positioned axially aligned with, and below, the cylindrical member, and is provided with a lifting movement for bottom-up loading the tubular knitted article onto the cylindrical member when the gripping and handling member is axially aligned with the cylindrical member, the cylindrical member being supported from the top above the gripping and handling member; and

an arrangement for angularly and axially positioning the toe of the tubular knitted article on the cylindrical member.
The device of claim 1, further comprising a closing machine for closing the toe of the tubular knitted article and preferably further comprising a transfer arrangement adapted to transfer the knitted article to the closing machine.
The device of claim 1 or 2, further comprising:
an opening chamber adapted to open the toe of the tubular knitted articles; and

a reversing tube with a vertical axis, adapted to reverse the tubular knitted articles pneumatically, and configured to be positioned below, and coaxially with, the opening chamber; wherein the gripping and handling member is adapted to be arranged below the opening chamber, between the opening chamber and the reversing tube, to engage with the toe of the tubular knitted article.
The device of claim 3, wherein the first cylindrical member and the reversing tube are configured to take an axial alignment position, where the reversing tube is arranged below the cylindrical member; wherein the reversing tube is provided with a movement from a position of axial alignment with the opening chamber to a position of axial alignment with the cylindrical member, and vice versa.
The device of one or more of the previous clams, comprising a plurality of cylindrical members supported on a conveyor, preferably a carousel rotating around a vertical axis, adapted to transfer each cylindrical member into a sequence of stations along a closed path.
The device of one or more of the previous claims, wherein a pneumatic feed duct for feeding the tubular knitted articles is associated with the opening chamber, the feed duct having an inlet and an outlet for the tubular knitted articles; wherein the outlet is arranged coaxial with, and above, the opening chamber; wherein preferably a converging-diverging duct is provided between the outlet of the tubular knitted articles and the opening chamber, the converging-diverging duct being coaxial with the outlet of the tubular knitted articles and the opening chamber; and wherein preferably the opening chamber is fluidly coupled to an annular duct surrounding the converging-diverging duct; wherein the annular duct is adapted to generate an air flow sucked from the inside of the converging-diverging duct in opposite direction with respect to the feed direction of the tubular knitted articles from the pneumatic feed duct to the opening chamber; and wherein preferably a pair of motorized rollers is provided opposite the outlet of the tubular knitted articles, the rollers defining a nip adapted to receive the tubular knitted articles and to move them forward from the outlet toward the opening chamber
The device of claim 6, wherein the pair of motorized rollers is provided between the outlet of the tubular knitted articles and the converging-diverging duct.
The device of claim 6 or 7comprising a plurality of air nozzles that are associated with the outlet of the tubular knitted articles, are arranged around an axis of the pneumatic feed duct, and are directed to converge toward the axis of the pneumatic feed duct and toward the opening chamber.
The device of one or more of the previous claims, wherein the gripping and handling member comprises a plurality of stretching fingers, which are provided with a movement toward and away from one another with respect to a vertical axis, and a plurality of pushing elements, which co-act with the stretching fingers for engaging with the toe of the tubular knitted article; and wherein the stretching fingers are directed upward so as to engage with the toe of a tubular knitted article positioned in the opening chamber.
The device of one or more of the previous claims, wherein the gripping and handling member is combined with an annular element, which is vertically movable parallel to the axis of the gripping and handling member, and is adapted to move through the gripping and handling member.
The device of one or more of the previous claims, wherein each cylindrical member comprises a plurality of stretching tabs, preferably four stretching tabs, which are extractable from, and retractable into, a side cylindrical surface.
The device of one or more of the previous claims, comprising an actuator configured to rotate each cylindrical member around an axis of the cylindrical member; preferably further comprising at least a gripper co-acting with each cylindrical member for pinching a tubular knitted article inserted onto the cylindrical member and allowing the cylindrical member to rotate around the respective axis by keeping the tubular knitted article stationary with respect to the gripper.
The device of one or more of the previous claims, comprising a detection system for detecting the axial and angular position of the tubular knitted article with respect to the cylindrical member, the detection system being preferably an optical system.
The device of one or more of the previous claims, where the transfer arrangement comprises: a plurality of stretching elements adapted to be inserted into the open toe of the tubular knitted article and to stretch the toe transversally to a longitudinal extension of the tubular knitted article so as to arrange it onto a sewing plane; and a longitudinal stretching device adapted to stretch the tubular knitted article longitudinally along the sewing plane; wherein preferably the stretching elements are configured to be inserted into the toe of the tubular knitted article with a downward movement; wherein preferably the stretching elements are carried by a first slide movable vertically with respect to the cylindrical member to insert the stretching elements into the toe of the tubular knitted article loaded onto the cylindrical member; and wherein preferably the transfer arrangement comprises a pair of blades arranged to engage with the tubular knitted article parallel to a sewing line that lies on the sewing plane, the pair of blades co-acting with the longitudinal stretching device for longitudinally stretching the tubular knitted article and preparing it for sewing; and wherein preferably the blades and the longitudinal stretching device are carried by a horizontally movable second slide adapted to insert the toe to be sewn of the tubular knitted article into a guide of the closing machine
A method for handling a tubular knitted article, particularly a sock, having a toe and an elastic edge, wherein the method includes the steps of:
arranging the tubular knitted article with the toe up and the edge down;

loading the tubular knitted article onto a cylindrical member through an upward movement, engaging the toe of the tubular knitted article with the cylindrical member;

angularly and axially positioning the tubular knitted article with respect to the cylindrical member;

transversally stretching the toe of the tubular knitted article on a sewing plane.
The method of claim 15, further comprising the following steps:
transferring the tubular knitted article to a closing machine; and

sewing the toe of the tubular knitted article in the closing machine.
The method of claim 16, further comprising the following steps:
feeding the tubular knitted article, with the toe ahead, from the top towards an opening chamber;

inserting the toe into the opening chamber;

opening the toe;

engaging the toe with a gripping and handling member;

reversing the tubular knitted article by inserting the edge of the tubular knitted article in a reversing tube arranged axially aligned with, and below, the opening chamber, by keeping the toe engaging with the gripping and handling member, the gripping and handling member being arranged between the opening chamber and the reversing tube;

aligning the gripping and handling member and the cylindrical member axially with respect to each other, with the cylindrical member above the gripping and handling member;

transferring the toe of the tubular knitted article upward from the gripping and handling member to the cylindrical member and performing the step of angularly and axially positioning the tubular knitted article with respect to the cylindrical member;

when the tubular knitted article is axially and angularly positioned with respect to the cylindrical member, performing the step of transversally stretching the toe of the tubular knitted article on a sewing plane and longitudinally stretching the tubular knitted article;

removing the tubular knitted article from the cylindrical member; and

inserting the toe into a guide of the closing machine.